Fastening means for u-shaped magnets in magnetic plate assemblies



May 8, 1951 2,551,947

R. C. HOFF FASTENING MEANS FOR U-SHAPED MAGNETS IN MAGNETIC PLATE ASSEMBLIES Filed June 25, 1949 3m entor HON/1L0 C. Her-F Gttomeg Patented May 8, 1951 FASTENING MEANS FOR U-SHAPED MAG- NETS IN MAGNETIC PLATE ASSEMBLIES Ronald C. Hofi, Erie, Pa., assignor to Eriez Manufacturing Company, Erie, Pa., a corporation of Pennsylvania Application June 25, 1949, Serial No. 101,433

Claims. 1

This invention relates generally to a magnetic plate assembly and more particularly to novel means for securing U-shaped magnets in a ma netic plate assembly.

Bolt and nut assemblies have heretofore been used for securing U-shaped magnets to a magnetic plate. It has heretofore been necessary to form built up portions on opposite sides of the magnet and core apertures through which the bolts may extend. Magnets now in use, known generally as Alnico magnets, are not machinable and there is considerable difiiculty in coring the holes for the bolts. Coring is performed with carbon cores which are expensive in themselves. Furthermore, the grains in the magnet are frequently set up directionally so that they follow the curvature of the magnet. Only the magnetic grains that lie along the line of magnetization are efficiently used. Where the grain structure is in the line of magnetization, the external energy produced is three times that of a similar magnet with the grain structure normal to the line of magnetization. Prior magnets do not provide for the effective use of a magnet with a grain structure in the line of magnetization. Expensive magnetic material must be used in prior magnets to provide bosses for bolt and nut assemblies. In prior magnetic plate assemblies, it has been necessary to form bolt holes in the plate and the head of the bolt projected from the plate so as to provide an uneven surface.

It is, accordingly, an object of my invention to overcome the above and other defects in present magnetic plate assemblies and it is more particularly an object of my invention to provide a magnetic plate assembly which is simple in construction, economical in cost, economical in manufacture, and efficient in operation.

Another object of my invention is to provide novel means for attaching U-shaped magnets to a plate without the use of bolts and nuts.

Another object of my invention is to provide novel means for fastening a U-shaped magnet to a plate wherein no apertured built up portions on the outer side of the magnet are required.

Another object of my invention is to provide a novel magnetic plate assembly wherein means are provided for attaching the magnets thereto without requiring the punching of holes in the plate.

Another object of my invention is to provide a magnetic plate assembly wherein the surface of the plate is smooth and has no projections thereon.

Another object of my invention is to provide a novel spring clip for attaching U-shaped magnets to a plate.

Another object of my invention i to minimize the amount of material required in a U-shaped magnet to provide a given magnetic force.

Another object of my invention is to utilize Fig. 3 is a perspective view of the plate in my novel magnetic plate assembly before the magnets are attached thereto; Fig. 4 is a fragmentary side elevational view of my novel magnetic plate assembly showing the magnets attached to the plate; and

Fig. 5 is a view taken on theline 55 of Fig. 4. Referring now to the drawings, I show in Figs. 1 to 5 inclusive a non-magnetic plate I having laterally and longitudinally spaced, oblong aper tures 2 for receiving the end face portions 3 and 4 of U-shaped magnets 5. The plate I has oppositely disposed, oppositely struck out portions 6 and 1 parallel to each other and spaced laterally from the apertures 2 in the plate I.

Each magnet 5 has oppositely disposed, inwardly extending shoulder portions 8 engageable by the offset curved ends 9 of a spring clip or plate ID. The struck out portions 6 and I of the plate I are bent over opposite sides of the central portion of the clip I 0 to secure the magnet 5 in a position as shown in Figs. 4 and 5 with the end faces 3 and 4 extending into the apertures 2 of the plate I. The lower portion of the clip I0 is spaced a predetermined distance from the face of the plate I when the curved end portions 9 thereof freely rest on the shoulder portions 8 of the magnet 5 so that when the struck out portions 6 and I are bent over opposite sides of the central portion of the clip In, it will be forced downwardly thereby tensioning the opposite ends thereof engaging the shoulders 8 of the magnet 5 to secure it firmly on the plate I. A second plate is disposed adjacent plate I and suitable pole pieces are provided on the ends of the pole faces 3 and 4 of the magnet 5 (not shown) It will be observed that the face of the plate I will be absolutely smooth inasmuch as there are no projecting bolt heads or any other projecting portions. all bolt and nut assemblies. A maximum amount of the extremely costly magnetic material is eliminated, greatly decreasing the cost thereof. My novel U-shaped magnet without any projections thereon is the closest approach to maximum efilcient use of zU-shaped magnets:-inasmuchlass the magnetic forces are in the direction of the grain structure of the magnet thereby increasing...

the eificiency thereof. The outer side of the magnet 5 is smooth and there are onlysmall project-1 ing shoulders 8 on the lower innersidesof the;

legs of the magnet 5, minimizing any leakage of magnetic lines of force. Fastening .members are struck out from the plate I thereby saving on material. The clip In is extremely simple in design and construction and is verycheap -in-cost.- Assembly of these magnets in my novel magnetic plate is simplified. My magnetic plate may be used as a magneticseparator in a chute or in any other like installation where a. smooth magnetic. plate is desirable. All'coring and other work' on the .magnet' 5 is eliminated thereby further decreasing the'cost of .the magnet. The amount of the costly magneticmaterial. in the magnet is greatly. decreased.

It-will beevident, from the foregoing description that I have provided a magnetic plate assembly which has novelmeans for. fastening the.

Various changes may be made in the'specifio embodimentof my invention, without, departing fromthe. spirit thereof. or from the scope .of the appended claims.

What .I claim. is: 1...In, amagnetic plate assemblyincludinga U- shaped magnet and fastening means therefor, in

combination, a non-magnetic .platehaving laterally spaced apertures von opposite. sides thereof,

opposed, outwardly struck straps transv.ersely...of said. .plate. and disposed between said apertures. a. U-shaped .magnet having. the .pole. .faces thereof. extendinginto said laterally spacedapertures and having oppositely-disposed, inwardly-extends,

ing. projeotions.- on ,the inner side of. thelegs. thereof, said magnet being mounted on said plate, and; a non-magnetic. clip spanning said projec-w tions-andz'mounted. thereon; secured intermeediatelythereof by said outwardly struck straps of. said non-magnetic.plates-to secure, said mag-,-= net onto said plate, said straps:engagingthe.side.

ofzsaid; clip opposite. said plate.

2., In a magnetic plate assembly as isetforth in. clai-m 1 whereiirthe portions of said clipengagingrsaid. inwardly directedprojections of: said-.1

magnet, are offset.

My novel fastening device eliminates 3. In a magnetic plate assembly including a U-shaped magnet and fastening means therefor, in combination, a flat non-magnetic plate having laterally spaced apertures on opposite sides thereof, opposed, outwardly struck straps transversely of said plate disposed between said apertures, said outwardly struck straps being struck out oppositely to each other in parallel relationship, a U-shaped magnet having the pole faces thereof extending partially into said laterallyaspaced apertures and having an inwardly di'rected shoulder on the inner side of each leg thereof, and. a non-magnetic clip engaging and spanningsaidsl'ioulders and mounted thereon secured by said straps on said plate to secure said netsspaced longitudinally fromv each other and.

having. the polefaces thereof disposed in the rec-. tangular shaped apertures in said plate for supportingsamathe lower inner side of each. of the legs of said -magnets being. offset defininga.

shoulder, andflexible non-magnetic clips engag-v ingandspanning opposed shoulders on each. of said magnets secured by the outwardly, struck straps. on said. plate,the ends of said straps extending over and contacting each of said straps-- 5.. In a magnetic plate assembly including a. U- shaped magnet andfastening, means therefor,- in combination, a fiatnon-magnetic plate having laterally spaced, apertures on opposite sides.- thereof, a U-shaped magnet having thepole faces. thereof extending partially into. said laterally spaced apertures and having an inwardly di-q rected shoulder on the inner side of each. legv thereof, a non-magnetic clip engaging andspanningsaid shoulders and mounted thereon,.and-.. fastening.v members extending outwardly from. said; plate: between saidapertures and engaging: the intermediate portion. of'said clip to attach said clip to, said plate to secure said U-shaped magnet to said plate.

RONALD C. HOFF.

REFERENCES CITED The following references are of record in thefile of this patent:

UNITED STATES PATENTS Name Date Brooks Feb. 24, 1948 Number rectangular, 

